typedef struct node{ int data;struct node *lchild,*rchild;}Bitree;
void swapbitree(Bitree *bt)
{
	Bitree *p;
	if(bt==0)
	{
		return;
	}
	swapbitree(bt->lchild);
	swapbitree(bt->rchild);
	p=bt->lchild;
	bt->lchild=bt->rchild;
	bt->rchild=p;
}
